Emissions Test Issue

EddieC · Sep 28, 2024

MikeZ71,
Holy cow!
So if someone took their car to a shop for a check engine light and the shop changed some parts related to the problem code and reset the light, would I be wrong in assuming that they just send the vehicle out "saying let's see how that goes" without that procedure?

Fless · Sep 28, 2024

The evap driving procedure is fairly standard, but most vehicles pass without having to do that all to a "t".

For the O2 issue, how many minutes does it take for the fuel system to go into closed loop? If the O2 heaters aren't working properly, you likely have bad fuel trims and a failed O2 activity and heater code.

Doubeleive · Sep 28, 2024

EddieC said:
It's hardly possible to drive 55 on highways here without getting run over.
It showed three "not readys" ; Evaporative system, oxygen sensor and oxygen sensor heated.
The code reset was related to Evap system.

Deleted comment after reading other posts.

ya you could probably do 60 and be ok, it's legal so just pretend to be gramma
I had to do it before, I survived got it smogged and about an hour later the cel came on again lol

EddieC · Sep 28, 2024

Fless said:
The evap driving procedure is fairly standard, but most vehicles pass without having to do that all to a "t".

For the O2 issue, how many minutes does it take for the fuel system to go into closed loop? If the O2 heaters aren't working properly, you likely have bad fuel trims and a failed O2 activity and heater code.

I don't believe the readout on the error code, P0449, (prior to the emission test) mentioned O2 sensors. It mentioned vent solenoid control circuit.
From reading that a code reset erases other data, I am assuming that the emission test "not ready" report on the O2 sensors could be related to the reset.

EddieC · Sep 28, 2024

MikeZ71,
On a quick peek on the status today I did see some "No"s listed but didn't write them down.

On the procedure that you posted, does that have to be done from a clean reset or do it anytime after some driving?

Also in the linked article it mentions "EVAP Service bay test".
Can you shed light on that?

mikez71 · Sep 28, 2024

To me, it sounds like you need to fix the P0449 code.
Sorry I don't know anything about that procedure, I just copy/pasted it from the Range disabler website.
BUT I would assume you can do it anytime.

First time I read your posts I saw you mention P0449 came back awhile after replacing purge valve.
Second time I missed that and thought it was in my head..
Third time I read it again and found where you mentioned it!

So it sounds like you could have a new bad valve..
Or maybe it wasn't an issue with the valve, but one with the hose or canister..

Personally, I would replace the canister anyways because I see so many posts about that..
And while you're in there check the hoses and valve if possible .
Purge valve should be closed when unpowered?
And I don't know how you would check the hose without removing it...Might have to pressurize or vacuum test the fuel tank w/hose?

EddieC · Sep 28, 2024

mikez71 said:
To me, it sounds like you need to fix the P0449 code.
Sorry I don't know anything about that procedure, I just copy/pasted it from the Range disabler website.
BUT I would assume you can do it anytime.

First time I read your posts I saw you mention P0449 came back awhile after replacing purge valve.
Second time I missed that and thought it was in my head..
Third time I read it again and found where you mentioned it!

So it sounds like you could have a new bad valve..
Or maybe it wasn't an issue with the valve, but one with the hose or canister..

Personally, I would replace the canister anyways because I see so many posts about that..
And while you're in there check the hoses and valve if possible .
Purge valve should be closed when unpowered?
And I don't know how you would check the hose without removing it...Might have to pressurize or vacuum test the fuel tank w/hose?

It threw the original P0449 code on a previous valve (if that's the one atop the engine) and three weeks later on the replacement.
I guess it took three weeks for the system to come back to ready.
So perhaps it might be something in the canister end of the system.

Fless · Sep 29, 2024

EddieC said:
It threw the original P0449 code on a previous valve (if that's the one atop the engine) and three weeks later on the replacement.
I guess it took three weeks for the system to come back to ready.
So perhaps it might be something in the canister end of the system.

P0449 has to do with the VENT valve circuit, not the purge valve on the engine. The vent valve (technically a solenoid, as is the purge valve unit) is located in the rear of the truck, near the spare tire. It vents the canister at certain times; the canister stores fuel vapors and vents "clean" air through the vent valve.

Most times that code is caused by a faulty vent valve, but not always. The solenoid might click but the valve that the solenoid controls might stay open or closed, instead of being actuated by the solenoid. It could be defective mechanically (solenoid or valve stuck) or electrically (solenoid not responding to open/close commands).

Easy enough to test; do you need references to test procedures? Here's one that show an electrical test; it's not your vehicle but the test would still be similar on yours. You don't need a Power Probe, just a 12vDC source to see if it clicks.

If I were you I'd just replace the vent valve with a quality new one. You can always test the old one on the bench.

j91z28d1 · Sep 29, 2024

EddieC said:
"Not ready" was reported as a failure and 90 days to retest. I don't know what happens if it's not ready again.

interesting.. what state do you live in. I wish er could sort out the specs for each state. I sware someone just passed theirs with the evap not ready before everyone else passed.

was yours just evap not ready. or others on the list not ready too.

EddieC · Sep 29, 2024

Fless said:
P0449 has to do with the VENT valve circuit, not the purge valve on the engine. The vent valve (technically a solenoid, as is the purge valve unit) is located in the rear of the truck, near the spare tire. It vents the canister at certain times; the canister stores fuel vapors and vents "clean" air through the vent valve.

Most times that code is caused by a faulty vent valve, but not always. The solenoid might click but the valve that the solenoid controls might stay open or closed, instead of being actuated by the solenoid. It could be defective mechanically (solenoid or valve stuck) or electrically (solenoid not responding to open/close commands).

Easy enough to test; do you need references to test procedures? Here's one that show an electrical test; it's not your vehicle but the test would still be similar on yours. You don't need a Power Probe, just a 12vDC source to see if it clicks.

If I were you I'd just replace the vent valve with a quality new one. You can always test the old one on the bench.

I have on oem on order. I can't afford therapy.
Good video.

Emissions Test Issue

EddieC

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Fless

Doubeleive

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EddieC

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EddieC

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mikez71

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EddieC

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Fless

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